The same HLA-DQ alleles determine either susceptibility or resistance to different coxsackievirus-mediated autoimmune diseases.

An important characteristic of autoimmune diseases is their association with major histocompatibility complex class I and class II alleles. In this study, we compared insulin-dependent diabetes mellitus (IDDM) with idiopathic dilated cardiomyopathy (IDC) from a strictly immunologic perspective. Although the target organs are different, being in one case the insulin-producing beta cells of the pancreas and in the other case the myocytes of the heart, many aspects of the tissue-specific immune destruction are common. Similar yet different Coxsackievirus B strains with either pancreotropic or cardiotropic specificity are able to perpetrate the first injury of the respective target tissue. Their shared capacity of inducing a superantigenic reaction further enhances the damage. Once previously secluded autoantigens are then exposed to the immune system, the tissue injury is completed via a more conventional type of immune response. On the basis of the compounded results we obtained, it is possible to propose that the same HLA-DQ molecules which are able to protect the individuals from IDDM (e.g., HLA-DQA1*0102, DQB1*0602) seem to favour the enteroviral attack to the myocardium, while alleles which confer the strongest susceptibility to IDDM (e.g., DQA1*0301, DQB1*0302), seem unable to sustain the immune attack against the heart.     

The leucine zipper of Aeromonas salmonicida AbcA is required for the transcriptional activation of the P2 promoter of the surface-layer structural gene, vapA, in Escherichia coli

The Aeromonas salmonicida AbcA protein is involved in the synthesis of the O-polysaccharide side-chains on the lipopolysaccharide and is also capable of enhancing the expression of the structural gene for the A-layer, vapA , when cloned into Escherichia coli . The P2 promoter of the vapA gene of A. salmonicida was cloned into a promoter probe vector and expression in E. coli was monitored. The expression of P2:: lacZ was shown to be increased when abcA was provided in trans . AbcA contains an N-terminal ATP-binding domain as well as a C-terminal leucine zipper domain. Site-directed mutagenesis has been used to show that the ATP-binding domain is required for the synthesis of the O-polysaccharide side-chains, but not for the enhancement of vapA expression. Conversely, the leucine zipper is needed for the increase in vapA expression, but not for O-polysaccharide side-chain synthesis. This indicates that AbcA is a bifunctional protein that can influence the synthesis of the two principle antigenic components of the A. salmonicida cell surface.     

Genetic restriction of the serum factor mediating tolerance in trinitrochlorobenzene hypersensitivity

Serum of mice which are tolerant to trinitrochlorobenzene (picryl chloride) inhibited the expression of hapten-specific cell-mediated immunity in vivo (delayed-type hypersensitivity) and in vitro (leukocyte adherence inhibition). These effects have now been demonstrated in three strains of inbred mice with different H-2 genotypes; in these mice the phenomenon was restricted to syngeneic cell-serum combinations. The serum factor mediating the effects in CBA mice was absorbed by the corresponding anti-Ia antiserum and by the specific hapten. The factor, which is found in serum and is demonstrable both in vivo and in vitro, thus appears to be antigen-binding and to have Ia determinants of the major histocompatibility complex.     

An improved method for the isolation of polysomes from synchronous macroplasmodia of Physarum polycephalum

An improved method for the isolation of polysomes from synchronous macroplasmodia of Physarum polycephalum is described. The procedure involves preincubation and homogenization of the macroplasmodia in high ionic strength media supplemented with high concentrations of Mg²⁺ and ethylene glycol bis (β-aminoethyl ether) N,N′-tetraacetic acid. The polysomes recovered from plasmodial postmitochondrial lysates or heavy particle fractions prepared in this way are sensitive to RNase and EDTA and more than 90% of the total single ribosome population is present as polysomes. The polysomes obtained could also be utilized as a beginning point for the isolation of poly(A)-containing RNA which showed a mass average sedimentation value of 18 S. The development of a satisfactory procedure for the isolation of intact polysomes and poly(A)-containing RNA from macroplasmodia should facilitate studies on mRNA metabolism and translational activity during a naturally synchronous mitotic division cycle.     

In situ hybridization to human chromosome 1 of a cDNA probe for the gene encoding the basement membrane heparan sulfate proteoglycan (HSPG)

A mouse partial cDNA clone of the heparan sulfate proteoglycan gene, an important component of basement membranes, has been mapped to human chromosome 1, band p 36.1, by in situ hybridization. No secondary sites of hybridization were observed.     

Summary of the 2000 Surgeon General's Listening Session: Toward a National Action Plan on Overweight and Obesity

Objective: To provide insight into discussions at the Surgeon General's Listening Session, “Toward a National Action Plan on Overweight and Obesity,” and to complement The Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity. Research Methods and Procedures: On December 7 and 8, 2000, representatives from federal, state, academic, and private sectors attended the Surgeon General's Listening Session and were given an opportunity to recommend what to include in a national plan to address overweight and obesity. The public was invited to comment during a corresponding public comment period. The Surgeon General's Listening Session was also broadcast on the Internet, allowing others to view the deliberations live or access the archived files. Significant discussion points from the Listening Session have been reviewed by representatives of the federal agencies and are the basis of this complementary document. Results: Examples of issues, strategies, and barriers to change are discussed within five thematic areas: schools, health care, family and community, worksite, and media. Suggested cooperative or collaborative actions for preventing and decreasing overweight and obesity are described. An annotated list of some programmatic partnerships is included. Discussion: The Surgeon General's Listening Session provided an opportunity for representatives from family and community groups, schools, the media, the health-care environment, and worksites to become partners and to unite around the common goal of preventing and decreasing overweight and obesity. The combination of approaches from these perspectives offers a rich resource of opportunity to combat the public health epidemic of overweight and obesity.